I found this: works perfectly and very fast. No headaches any more:
https://github.com/robwent/elementor-css-regenerator
That didn’t work. I resorted to putting the booking form on a separate page. Also, loading the form in a popup caused a considerable delay in loading the start page, as popups are (normally) preloaded in Elementor.
Update:
It seems the jQuery-events are not attached, looks like fbuilderJquery is not called for the popup-form.
